DefinitionA peptic ulcer is erosion in the lining of the stomach or the first part of the small intestine, an area called the duodenum.If the peptic ulcer is located in the stomach it is called a gastric ulcer.See also:GastritisGastroesophageal reflux disease (GERD)Alternative NamesUlcer - peptic; Ulcer - duodenal; Ulcer - gastric; Duodenal ulcer; Gastric ulcer; Dyspepsia - ulcersCauses, incidence, and risk factorsNormally, the lining of the stomach and small intestines are protected against the irritating acids produced in your stomach. If this protective lining stops working correctly, and the lining breaks down, it results in inflammation (gastritis) or an ulcer.Most ulcers occur in the first layer of the inner lining. A hole that goes all the way through the stomach or duodenum is call